Global Approaches to Elucidate the Function of Post-transcriptional Networks in HIV-1 Infection

人类免疫缺陷病毒1型（HIV-1）是获得性免疫缺陷综合征（艾滋病）的病原体，艾滋病是我们时代最重要的流行病之一。在6 000万感染艾滋病毒-1的人中，有2 500万人死亡。过去，在更好地了解HIV-1感染方面取得了非常重要的进展。然而，在过去十年中取得的技术发展现在打开了以前所未有的深度探索受感染细胞的可能性。一旦HIV-1渗透到宿主细胞中，病毒颗粒就会分解，释放出被病毒和宿主蛋白质覆盖的基因组RNA。这种蛋白质-RNA复合物向细胞核移动，在此过程中，HIV-1基因组RNA被逆转录成DNA，形成前病毒。一旦进入细胞核，前病毒就整合到细胞染色体中。新合成的HIV-1 RNA的合成、加工和转运回细胞质由宿主机制介导。重要的是，HIV-1 RNA的翻译由细胞蛋白质合成机制发挥作用，产生产生病毒后代所需的病毒蛋白质。因此，HIV-1从进入感染细胞到释放病毒后代都依赖于细胞资源。由于HIV-1强烈依赖于宿主基因表达机制，科学家们设想，抑制病毒复制所需的细胞功能并且不损害细胞存活，将代表治疗HIV-1感染的替代策略。RNA结合蛋白是基因表达机制的关键“参与者”，这类蛋白已成为HIV-1感染的关键调节因子。然而，为了确定新的治疗靶点，科学家们必须首先确定参与HIV-1复制的细胞蛋白的确切库。迄今为止，尽管为更好地了解HIV-1与宿主细胞的相互作用进行了大量的努力，但这一宿主因素目录仍然不完整。我在博士后工作期间开发的方法现在提供了在全球范围内定义与HIV-1基因组RNA直接相互作用的宿主蛋白质范围的可能性。将使用不同的生物化学方法在培养细胞和小鼠模型中详细研究通过这些方法鉴定的蛋白质库。通过这些分析证明在HIV-1复制中起重要作用的蛋白质可能代表治疗感染的潜在宿主靶点。因此，该项目旨在通过使用新的全系统方法扩展我们在HIV-1生物学方面的知识来寻找潜在的治疗靶点。

Human immunodeficiency virus type 1 (HIV-1) is the causative agent of Acquired Immunodeficiency Syndrome (AIDS), which constitutes one of the most important pandemics of our time. From the 60 million people that have been infected with HIV-1, 25 million have dead. Very important advances have been done to better understand HIV-1 infection in the past. However, the technical developments achieved in the last decade open now the possibility of exploring an infected cell in an unprecedented depth. Once HIV-1 penetrated into the host cell the viral particles disassemble, releasing the genomic RNA that is covered by viral and host proteins. This protein-RNA complex travels towards the nucleus and, during the path, HIV-1 genomic RNA is reverse transcribed into DNA to form the provirus. Once in the nucleus, the provirus is integrated into the cellular chromosome. Synthesis, processing and transport back to the cytoplasm of newly synthesized HIV-1 RNAs are mediated by the host machinery. Importantly, translation of HIV-1 RNAs is exerted by cellular protein synthesis machinery, producing the viral proteins required to generate the viral progeny. Therefore, HIV-1 relies on cellular resources from the entrance in the infected cell to the release of viral progeny. Because HIV-1 strongly relies on host gene expression machinery, scientists envision that inhibition of a cellular function that is required for viral replication and does not compromise cell survival, will represent an alternative strategy to treat HIV-1 infection.RNA-binding proteins are key "players" of gene expression machinery and this protein class has emerged as crucial regulators of HIV-1 infection. However, to identify novel therapeutic targets, scientists have first to determine the exact repertoire of cellular proteins involved in HIV-1 replication. To date this catalog of host factors is still incomplete in spite of the numerous efforts undertaken to better understand HIV-1-host cell interactions. The methods that I developed during my postdoctoral work offer now the possibility to globally define the scope of host proteins that directly interact with HIV-1 genomic RNA. The repertoire of proteins identified by these methods will be studied in detail in cultured cells and mouse models using different biochemical approaches. Proteins proven by these analyses to play an essential role in HIV-1 replication may represent potential host-based targets to treat the infection. Therefore, this project aims at finding potential therapeutic targets by expanding our knowledge in HIV-1 biology using novel system-wide approaches.